AD 97-07-14

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A320 series airplanes, that requires modification of an area on the front spar of the wing center section by installing shims and new fasteners to reinforce pressure floor fittings. This amendment is prompted by a report from the manufacturer indicating that full-scale fatigue testing on the test model revealed fatigue cracking in this area. The actions specified by this AD are intended to prevent fatigue cracking in this area, which can reduce the structural integrity of fuselage frame 36 and the wing center section.

Final rule.

97-07-14 AIRBUS INDUSTRIE: Amendment 39-9988. Docket 96-NM-105-AD.

Applicability: Model A320 series airplanes as listed in Airbus Service Bulletin A320-57- 1013, Revision 1, dated September 29, 1992; certificated in any category.

NOTE 1: This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent fatigue cracking in the rib flange of the front spar side of the wing center section, and consequent reduced structural integrity of fuselage frame 36 and the wing center section, accomplish the following:
(a) Prior to the accumulation of 16,000 total landings, or within 3 months after the effective date of this AD, whichever occurs later, modify the rib flange on the front spar of the wing center section by installing shims and new fasteners to reinforce pressure floor fittings, in accordance with Airbus Service Bulletin A320-57-1013, Revision 1, dated September 29, 1992.

NOTE 2: Modification of the rib flange accomplished prior to the effective date of this AD in accordance with Airbus Service Bulletin A320-57-1013, dated April 12, 1989, is considered acceptable for compliance with the modification required by this AD.

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113.

NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113.

(c) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

(d) The modification shall be done in accordance with Airbus Service Bulletin A320-57-1013, Revision 1, dated September 29, 1992, which contains the following list of effective pages:

Page Number
Revision Level
Shown on PageDate
Shown on Page
1-3
1
September 29, 1992
4-11
Original
April 12, 1989

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

(e) This amendment becomes effective on May 12, 1997.

A proposal to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) to include an airworthiness directive (AD) that is applicable to certain Airbus Model A320 series airplanes was published in the Federal Register on January 21, 1997 (62 FR 2982). That action proposed to require modification of an area on the front spar of the wing center section by installing shims and new fasteners to reinforce pressure floor fittings.

Interested persons have been afforded an opportunity to participate in the making of this amendment. Due consideration has been given to the single comment received.

The commenter supports the proposed rule.

Conclusion
After careful review of the available data, including the comments noted above, the FAA has determined that air safety and the public interest require the adoption of the rule as proposed.

Cost Impact
The FAA estimates that 5 Airbus Model A320 series airplanes of U.S. registry will be affected bythis AD, that it will take approximately 13 work hours per airplane to accomplish the required actions, and that the average labor rate is $60 per work hour. Required parts will cost approximately $576 per airplane. Based on these figures, the cost impact of the AD on U.S. operators is estimated to be $6,780, or $1,356 per airplane.

The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the requirements of this AD action, and that no operator would accomplish those actions in the future if this AD were not adopted.

Regulatory Impact
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

For the reasons discussed above, I certify that this action (1) is not a "significant regulatory action" under Executive Order 12866; (2) is not a "significant rule" under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and (3) will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act. A final evaluation has been prepared for this action and it is contained in the Rules Docket. A copy of it may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39)as follows:
PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701.
39.13 - [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: